Automotive construction engine and lifting column for a contruction engine

Abstract

A road construction machine includes a machine frame, a working drum and a plurality of ground engaging supports. A plurality of lifting columns are connected between the machine frame and the ground engaging supports. Each of the lifting columns include two telescoping hollow cylinders. A plurality of lifting position measuring devices are provided, each measuring device being coupled with elements of one of the lifting columns, which elements are capable of being displaced relative to one another in accordance with the lifting position of the lifting column in such a manner that a path signal pertaining to a lifting position of the lifting column is continuously detectable by the measuring device. A controller is operably connected to the lifting position measuring devices to receive the path signals and to regulate the lifting positions of the lifting columns in response to the path signals.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to an automotive construction machine as well as a lifting column for a construction machine.[0002]Such construction machinery is known, for instance, from DE 103 57 074 B3. The said construction machine shows a machine frame that is supported by a chassis, as well as a working drum that is mounted at the machine frame in an immovable and / or pivotable manner, and is used for working a ground surface or traffic surface. The chassis is provided with wheels and / or crawler track units which are connected to the machine frame via lifting columns and are individually adjustable in height relative to the machine frame.[0003]The adjustment in height is made possible by a controller that raises or lowers the lifting columns by controlling the hydraulic input or hydraulic discharge of piston cylinder units in the lifting columns.[0004]The construction machine described in DE 103 57 074 B3 is a recycler, and the disclosure of this publicat...

AI Technical Summary

Benefits of technology

[0013]The invention provides in an advantageous manner for pre-selectable positions of the lifting columns to be adjusted in a regulated manner, permitting the use of the measured path signal, and of the velocity and acceleration signals which can be deduced therefrom. Recording of the measured values enables the lifting state of the lifting columns to be regulated automatically. A controller receiving the measured signals from the measuring device can adjust a desired lifting position of the lifting columns in a regulated manner without overshooting or with as little overshooting as possible in accordance with the measured signals of the measuring device and / or their alteration over time.

[0023]Recording of the measured values enables a controller, which receives the measured signals from the measuring devices, to regulate the lifting state of the lifting columns automatically in such a manner that the machine frame is subject to the smallest possible displacement due to the structure of the ground surface or traffic surface.

[0030]A controller receiving the measured signals from the measuring devices can adjust a desired lifting position of the lifting columns without overshooting or with as little overshooting as possible in accordance with the measured signals from the measuring devices and / or their alteration over time.

Problems solved by technology

When the piston has left the pre-defined sensor positions, the information about the position of the machine is lost.

It is, in particular, not possible to adjust any other operating positions in a flexible manner without remounting the position sensors.

It is not even possible to, for instance, adjust an operating position that is parallel to the pre-adjusted operating position but deviates from the same in height.

What is more, it is not possible to adjust a defined transverse inclination or any other practical position of the machine frame or the machine respectively without cumbersome remounting efforts.

This creates the additional problem that the machine frame can adopt a different distance to the ground surface or traffic surface because of different loads or load distributions which are due to, for instance, a different filling level of the fuel tank or a water tank.

In case of wheels, deviations additionally result because of the filling pressure, the temperature and the interaction of the relatively soft wheel with the ground surface or traffic surface, which may, for instance, cause an alteration in distance of several centimetres.

Even though it is also possible to unlock the sensor for the operating position and to override this lifting position, the disadvantage results that the piston, at its front surfaces, touches the respective front surfaces of the cylinder when the mechanical limit stop of the piston cylinder unit has been reached, which may cause the piston of the piston cylinder unit to turn loose when carrying out steering movements of the wheels.

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